Taehoon Kim
Hanyang University, Republic of Korea
Bio:
- Graduate student, Department of Food and Nutrition, Hanyang University, Republic of Korea
- Published research: Association of fermented food intake with the prevalence of depressive symptoms and suicidal ideation in men and women stratified by age using KNHANES 2014–2022 data (Frontiers in Nutrition, 2026)
Abstract:
Background: Probiotics are known to improve depressive symptoms through gut-brain axis, but the effects of postbiotics on depressive symptoms and tryptophan and tyrosine metabolites are unknown. Thus, the present study aimed to investigate the hypothesis that supplementation of postbiotics improved depressive symptoms, gut microbiota composition, and fecal tryptophan and tyrosine metabolites in young adults with depressive symptoms.
Methods: In the randomized, double-blind, placebo-controlled, parallel-group trial, fifty-two participants aged 19–39 years with Center for Epidemiologic Studies Depression Scale–Korean version (CES-D-K) scores ≥16 were recruited. Participants were randomly assigned to take three gummies per day of either placebo or postbiotics, providing a total of 2 × 1010 CFU/day for 8 weeks.
Results: Supplementation of postbiotics improved CES-D-K scores (p = 0.034) and Depression Anxiety Stress Scales–21 depression scores (p = 0.024), and changed beta-diversity (p = 0.039) with higher relative abundances of Oscillospiraceae (p = 0.033) and Bifidobacteriaceae (p = 0.044). Supplementation of postbiotics also increased the fecal concentrations of 5-hydroxytryptophan (p = 0.021), indole-3-lactic acid (p = 0.037), indole-3-carboxaldehyde (p = 0.009), 3-indoleacrylic acid (p = 0.007), and tyrosine (p = 0.037). In addition, supplementation of postbiotics improved bloating and flatulence (p = 0.023), vomiting and nausea (p = 0.021), and incomplete evacuation of the bowel passage (p = 0.006).
Conclusions: The present study showed that supplementation of postbiotics improved depressive symptoms, gut microbiota composition, and fecal tryptophan metabolites and tyrosine in young adults with depressive symptoms.
